Videophone products have been available to consumers for a number of years. However, earlier videophone products usually required a use of Integrated Service Digital Network (ISDN) digital phone lines which have a broader bandwidth than analog telephone lines, i.e., Public Switching Telephone Network (PSTN) phone lines. Communications over the ISDN digital phone lines are expensive, and they are not universally available.
With the advent of relatively fast modems, e.g., 28.8 k bps modems, it became possible to send video as well as audio information over the PSTN analog phone lines. However, the use of videophones over the PSTN analog phone lines had many drawbacks.
First, because of the bandwidth limitation and lack of defined standard of video quality, the quality of the video was very poor. Second, because of a lack of standardization of communications protocol, manufacturers were producing videophone products that are not interoperable with each other, i.e., a videophone manufactured by one manufacturer was not able to communicate with another videophone manufactured by another manufacturer.
In order to allow for an interoperable, quality audiovisual communications over a PSTN analog phone line, the International Telecommunications Union (ITU) recently has adopted a new standard called H.324. The H.324 protocol, adopted by the ITU, is now the standard for audiovisual/multimedia communications over the PSTN analog phone lines. This new standard allows for interoperability and high quality video, voice, and data based phone calls. The H.324 standard makes it possible for a common method transmission of video, voice, and data simultaneously over a high-speed modem connection.
Ever since the adoption of the H.324 standard, some products based on this new standard have become available to consumers, and others are being developed by various different manufacturers. Some of the applications these new products are directed to are video conferencing, remote video surveillance, security system monitoring and closed circuit television (CCTV). In addition, there are needs for products which can be used in fire control and home automation applications.
Even though there are some products in the market place today that are designed for one or more of the above applications, there is no product which could provide capabilities to perform all six of the above functions simultaneously. In addition, use of these products are cumbersome because they do not provide a dedicated interface unit, instead relying on a telephone keypad or a computer keyboard for user control input and a phone headset or a computer for transmitting and receiving voice. Furthermore, many of these products require a use of a computer for proper operation. Therefore, there is a current need for a self-contained video transceiver for multi-functional applications.
An embodiment of the present invention is directed to a video transceiver which satisfies this need. In one embodiment, a video transceiver includes a keypad for entering a telephone number, and a transceiver circuit capable of formatting a video input, an audio input and the entered telephone number for transmission on a PSTN telephone line. The transceiver circuit is also capable of extracting a PSTN telephone line input comprising a video signal, an audio signal and a telephone number identifying the video transceiver. Preferably, the video transceiver includes an indicator which indicates when the telephone number identifying the video transceiver is extracted by the video transceiver.
In alternative embodiments of the present invention, the video transceiver is employed in numerous applications. By way of example, in one embodiment, a video transceiver having a keypad is coupled to a detector and an indicator which is responsive to the detector. The video transceiver includes a transceiver circuit which dials a telephone number in response to the detector, and couples an output of the detector to a PSTN telephone line. Preferably, an interface module is used to couple the detector and the indicator to the video transceiver. A video camera output may also be coupled to the PSTN telephone line through the video transceiver in response to the detector and recorded by a video cassette recorder.
In an alternative embodiment, a video transceiver is coupled to the PSTN telephone line. The video transceiver includes a keypad and a transceiver circuit capable of extracting an appliance control signal from the PSTN telephone line. An appliance, responsive to the extracted appliance control signal, is coupled to the video transceiver. Preferably, an interface module is used to couple the video transceiver to the appliance.
In another embodiment, a video transceiver is coupled to the PSTN telephone line. The video transceiver includes a keypad and a transceiver circuit capable of extracting a number of appliance control signals from the PSTN telephone line. The appliances are preferably coupled to the video transceiver through an interface module, and are responsive to their respective extracted appliance control signals.
In yet another embodiment, a multiplex video transceiver is coupled to a number of keypad controllers. Each keypad controller is coupled to a video camera, a television monitor, a speaker, and a microphone. The multiplex video transceiver is coupled to a video transceiver having a keypad on a PSTN telephone line. Preferably, the video transceiver also includes a video camera, a television monitor, a speaker, and a microphone.
The described embodiments are multi-functional systems capable of performing video conferencing, remote video surveillance, security system monitoring, and CCTV applications as well as capabilities for fire control and home automation. The dedicated keypad of the video transceiver eliminates the need for using a telephone keypad for user control. Finally, the integration of a speaker and microphone into the video transceiver eliminates the need to rely on a telephone headset or a computer for voice communications.
It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only embodiments of the invention by way of illustration of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.